In a surveillance or monitoring system that comprises one or more monitoring cameras being under the control of an operator who is interacting with a camera control unit, it is in most scenarios very important that the operator is able to identify and follow (e.g. on a display device) a moving object of interest in a monitored scene. Typically, a camera in a monitoring system is configured such that it can rotate around a tilt axis and rotate around a pan axis and also configured to zoom a lens attached to the camera. An often used acronym for such a camera is PTZ, where “P” represents pan, “T” represents tilt and “Z” represents zoom. Small electronic motors are typically used to provide the necessary rotation/movement in pan, tilt and zoom and the operator is typically operating an appropriate user input device such as a computer mouse or joystick in order to provide adjustment signals for controlling the pan, tilt and zoom motors.
It is easily envisaged that it is difficult for operators of such PTZ configured cameras to manually follow/track moving objects in a scene with the PTZ camera if objects in the scene are moving in a non-optimal direction. A non-optimal direction is a direction that requires more than one camera motor to move, e.g. rotation in both pan and tilt simultaneously. This is independent of whether the input device is a mouse or a joystick. It will be even more difficult for the operator in case the camera shall be zoomed so the object covers a large portion of the current field of view on the display (e.g. be zoomed in enough). Needless to say, fast moving objects such as vehicles are sometimes extremely difficult to follow.
The prior art comprises the international patent application publication WO 2010/064445 A1, which describes a camera device with a rotation table. Position and speed for a detected object is used in combination with a detected manual operation speed of the rotation table for assisting an operator to track the object.